According to data from Trend Stream and Lightspeed Research, nearly 80 million people uploaded photos in November last year and 15% put video online.
Most of this material is personal, but often it’s also business content.
Both companies also recently found in their Global Web Index that watching video online has become mainstream.
Almost 70% of U.S. web surfers watch video clips online and 19% share online video with others.
More data (PDF) here.
I found an interesting presentation about modelling user interactions in online social networks. It was posted four days ago by a collaborator of the Seoul National University and presented at the Asian workshop of social web and interoperability in December.
The presentation looks at the definition of online friends and the interaction between (social) users.
The authors divide the social networks according to four criteria and axes: functional (like LinkedIn), user profile focused, entertaining and interest focused.